Caption: Meiosis. Computer artwork of anaphase (I) during meiosis (gamete formation). Pairs of homologous chromosomes (orange) are being pulled to opposite ends of the cell by spindles (purple). This results in two cells with half the usual number of chromosomes. During meiosis four daughter nuclei are formed from one parent nucleus after two stages of nuclear division. Meiosis occurs only in the sex cells (gametes) of the testes and ovaries. The full complement of chromosomes is restored when two gametes fuse during fertilisation.